Enantiomeric cannabidiol derivatives: synthesis and binding to cannabinoid receptors

(-)-Cannabidiol (CBD) is a major, non psychotropic constituent of cannabis. It has been shown to cause numerous physiological effects of therapeutic importance. We have reported that CBD derivatives in both enantiomeric series are of pharmaceutical interest. Here we describe the syntheses of the major CBD metabolites, (-)-7-hydroxy- CBD and (-)-CBD-7-oic acid and their dimethylheptyl ( DMH) homologs, as well as of the corresponding compounds in the enantiomeric (+)-CBD series. The starting materials were the respective CBD enantiomers and their DMH homologs. The binding of these compounds to the CB1 and CB2 cannabinoid receptors are compared. Surprisingly, contrary to the compounds in the (-) series, which do not bind to the receptors, most of the derivatives in the (+) series bind to the CB1 receptor in the low nanomole range. Some of these compounds also bind weakly to the CB2 receptor.